Packer and associated methods, seal ring and fixing ring

ABSTRACT

A downhole seal system comprising at least one a deformable member; and at least one expandable seal; wherein the deformable member is provided proximate, adjacent, against, or fixed to the expandable seal. Optionally, the expandable seal is or comprises a swellable seal and/or the deformable member comprises or at least partially defines a seal receiving groove and at least part of the expandable seal is received or receivable within the seal receiving groove such that the expandable seal is expandable so as to deform the deformable member and thereby increase an outer diameter or extent of the deformable member. Also described is an associated deformable member and fixing member and associated methods for producing and using the seal system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase under 35 U.S.C. 517 371 of PCTInternational Application No. PCT/GB2014/051342 which has anInternational filing date of Apr. 30, 2014, which claims priority toUnited Kingdom No. GB 1308067.6, filed May 3, 2013, the entire contentsof each of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a seal system such as a packer/slide onsleeve, a seal ring for a packer, a fixing ring for a packer andassociated methods of manufacture and use.

BACKGROUND OF THE INVENTION

Downhole packers are commonly used downhole in applications such asisolating zones in a wellbore. Such packers may comprise swellablecomponents that swell under the action of fluid in the well bore to forma seal between a pipe to which it is attached and the inside diameter ofthe wellbore or bore casing.

The seal quality of the packer is an important factor in packer design.Improving the seal quality can allow the packer to operate at andwithstand higher pressures or allow a shorter packer to be used at thesame differential pressure.

Patent documents US 2011/0088892A1, GB 2427420A, US 2010/0288486A1, WO2011/020987A2, and EP 2246522A3 suggest the use of an intermediatemember between an end ring and a seal in order to improve the quality ofthe seal.

SUMMARY OF THE INVENTION

According to a first aspect of the invention is a downhole seal system,such as a packer or slip on sleeve. The seal system may be configured tobe mounted on a pipe or other elongate structure. The seal system may beconfigured to seal between the pipe or other structure and walls orcasing of a hole, conduit or borehole in which the seal system islocated.

The seal system may comprise at least one and preferably two (i.e. firstand second) end members.

The seal system may comprise at least one seal, which may be configuredto seal against the walls or casing of the hole, conduit or borehole inwhich the seal system is located. The seal may be at least partiallydisposed between the end members. At least part of at least one andpreferably each end of the seal may be provided proximate, adjacent orin contact with or fixed to a respective end member.

The end members may comprise cylindrical or annular members. The endmembers may comprise inner and outer surfaces. The inner surface may atleast partially define a passage having openings at opposing ends of theend member. The passage may be configured to receive the pipe or otherstructure upon which the seal system is mountable.

The seal may be annular and/or cylindrical. The seal may at leastpartially define a through passage, which may be for receiving the pipeor other structure upon which the seal system is mountable. The seal maycomprise an expandable seal such as a swellable seal. The swellable sealmay be selectively or preferentially swellable in selected fluids, whichmay comprise fluids found downhole, such as oil and/or water or wet gas.The expandable seal may be swellable or expandable to seal against thewalls or casing of the hole, conduit or borehole when swollen.

The passages of the end members and the seal may be aligned to form athrough passage of the seal system configured to receive the pipe orother structure upon which the seal system is mountable. In this way,the seal system may be in the form of a sleeve for mounting on the pipeor other structure.

The seal device may comprise at least one deformable member, such as aseal ring. At least one deformable member may be comprised in at leastone and preferably each of the end members. The deformable member maycomprise an annular member or ring. The deformable member may compriseor be formed from a non-metallic material such as an elastomericmaterial, such as PTFE, Viton, a hydrogenated nitrile compound such ashydrogenated nitrile butadiene rubber (HNBR), highly saturated nitrile(HSN) or the like.

The deformable member may be provided adjacent, proximate, against,fixed to or embedded in the seal.

The deformable member may comprise or at least partially define a sealreceiving groove or recess which may comprise a concave groove orrecess. The seal receiving groove may be provided on a surface of thedeformable member, such as a side surface. In particular, the sealreceiving groove may be provided on a surface of the deformable memberthat faces the seal.

The seal receiving groove may comprise a substantially V-shaped groove.The seal receiving groove may be at least partially defined by at leastone leg, such as an upper or outer leg, and preferably by at least twoopposing legs. The opposing legs may comprise the upper or outer leg anda lower or inner leg, wherein the upper or outer leg is providedradially outwardly of the lower or inner leg. The upper or outer leg maycomprise the leg furthest from the pipe or through passage, whilst thelower or inner leg may comprise the leg closest to the pipe or throughpassage.H

The seal receiving groove may be asymmetric in cross section. One of thelegs may have a different radius of curvature to the other leg. One ofthe legs, which may be the upper or outer leg, may extend further fromthe body of the deformable member than the other leg (e.g. the lower orinner leg). This may allow the upper or outer leg to bridge a larger gapbetween the end member and the wall of the bore, conduit or casing.

One of the legs (which may be the upper or outer leg) or a face thereofmay extend at a different angle to the other leg (e.g. the lower orinner leg) or a face thereof. One of the legs (which may be the upper orouter leg) or a face thereof may extend at a smaller angle to thehorizontal than the other leg (e.g. the lower or inner leg) or a facethereof. For example, the outer leg or a face thereof may extend at anangle to the horizontal that is between 20 and 70% greater than theangle to the horizontal at which the lower leg or a face thereofextends. In a more specific example, the upper leg or a face thereof mayextend at between 10° and 30° above horizontal, whilst the lower leg ora face thereof may extend between 20° and 40° below horizontal.

The end member may comprise a fixing member such as an end ring. Thedeformable member may be mounted on or adjacent to the fixing member.The fixing member may be annular. The fixing member may be rigid. Thefixing member may be metallic.

The end member may be configured such that the fixing member abuts or isadjacent or fixed to the deformable member.

The fixing member may comprise a recess, such as a concave recess, forat least partially receiving the deformable member. The recess maycomprise a groove, which may be in the form of a substantially v-shapedgroove. The recess may open by an angle of between 50° and 100°,preferably between 60° and 90° and most preferably between 70° and 80°.

A surface of the deformable member that faces the fixing member, whichmay be a surface opposite the surface of the deformable member on whichthe seal receiving recess is provided, may be shaped to fit into therecess of the fixing member, for example by comprising a protrudingprofile, which may comprise a complimentary profile to that of therecess. The deformable member may have a cross section in the form of achevron or a distorted or asymmetrical chevron.

The fixing member may be fixed or fixable to the pipe or otherstructure. The fixing member may comprise one or more fixing elements,such as set or grub screws, for selectively fixing the fixing member tothe pipe or other structure.

At least part of at least one and preferably each end of the seal may beoutwardly protruding or beveled so as to at least partially extend intothe seal receiving groove of the deformable member and may extend atleast partially between the legs of the deformable member.

The seal system may be configured such that as the seal expands, theseal applies a force to the opposing legs of the seal receiving grooveof the deformable member so as to deform the deformable member, whichmay comprise pushing the opposing legs apart. The expansion of the sealmay apply a force that acts to push the upper or outer leg of the sealreceiving recess of the deformable member radially outwardly. The sealsystem may be configured such that deformation of the deformable memberdue to expansion of the seal may increase the outer diameter or extentof the deformable member. In this way, as the seal expands, theexpansion of the seal may apply pressure on the legs of the deformablemember that may force the opposing legs apart so as to increase theouter diameter or extent of the deformable member. This in turn may actto close any gaps between the deformable member and surfaces of the borewall, casing or conduit in which the seal system is located. As aresult, the deformable member may be operable as an additional orback-up seal. The deformable member may also help to guide the swellingor expansion of the seal radially outwardly, may support the seal andmay prevent extrusion of the seal through gaps between the end membersand the bore wall, casing or conduit, particularly under high pressuredifferentials or flow often found downhole, particularly in deep bores.

Furthermore, this configuration may allow a greater tolerance orclearance between the outer diameter of the end members in an initialstate (i.e. when the seal is unswollen or unexpanded) and the innerdiameter of the bore, casing or conduit. Thereby, the device may beeasier to insert into place without getting stuck but at the same timesuitably inhibit extrusion of the outer seal when the seal is expandedand the deformable member has been deformed. This may facilitate ahigher expansion ratio of the seal(s) and allow easier insertion of theseal device past restrictions and narrow portions of the bore or conduitwithout jamming.

The improved sealing quality that results from this configuration mayallow a shorter packer length to be used for similar sealing performanceto that of a larger conventional packer or may allow higher operationalpressures at a similar length of packer to be achieved.

According to a second aspect of the present invention a deformablemember is provided for use with a seal system, such as the seal systemof the first aspect. The deformable member may comprise an annularmember or ring. The deformable member may comprise or be formed from anon-metallic material such as an elastomeric material, for example,PTFE, Viton, HNBR or the like. The deformable member may be operable asa seal ring, such as a secondary or back-up seal ring. The deformablemember may comprise a seal receiving groove, such as a concave groove.The seal receiving groove may be an annular groove. The seal receivinggroove may be provided on a surface of the deformable member, such as aside surface.

The seal receiving groove may comprise a substantially V-shaped groove.The seal receiving groove may be partially defined by at least twoopposing legs. The opposing legs may comprise an upper or outer leg anda lower or inner leg, wherein the upper or outer leg is providedradially outwardly of the lower or inner leg. The seal receiving groovemay be asymmetric in its cross section. One of the legs may have adifferent radius of curvature to the other leg. One of the legs, whichmay be the upper or outer leg, may extend further from the body of theelastomeric member than the other leg (e.g. the lower or inner leg). Oneof the legs (which may be the upper or outer leg) or a face thereof mayextend at a different angle to the other leg (e.g. the lower or innerleg) or a face thereof. One of the legs (which may be the upper or outerleg) or a face thereof may extend at a lower angle to the horizontalthan the other leg (e.g. the lower or inner leg) or a face thereof. Forexample, the outer leg or a face thereof may extend at an angle to thehorizontal that is between 20 and 70% greater than the angle to thehorizontal at which the lower leg or a face thereof extends. In a morespecific example, the upper leg or a face thereof may extend at between10° and 30° above horizontal, whilst the lower leg or a face thereof mayextend between 20° and 40° below horizontal.

A surface of the deformable member opposite the surface on which theseal receiving recess is provided may comprise a protruding profile. Thedeformable member may have a cross section in the form of a chevron or adistorted chevron. According to a third aspect of the present inventiona fixing member is provided for use in a seal system, such as the sealsystem of the first aspect.

The fixing member may comprise or form an end ring.

The fixing member may comprise an annular member. The fixing member maycomprise or form an end ring. The fixing member may be rigid. The fixingmember may be metallic.

The fixing member may comprise a recess for at least partially receivinga deformable member. The recess may be provided on a side surface of thefixing member. The recess may comprise a substantially v-shaped groove.The recess may open by an angle of between 50° and 100°, preferablybetween 60° and 90° and most preferably between 70° and 80°.

According to a fourth aspect of the present invention is a method forproducing a seal system, such as the seal system of the first aspect.The method may comprise providing a deformable member according to thesecond aspect. The method may comprise providing a fixing memberaccording to the third aspect proximate or adjacent or fixed to orbutting against the deformable member. The method may comprise providingthe protruding profile of the deformable member at least partiallywithin the recess of the fixing member.

The method may comprise providing an expandable seal, such as aswellable seal, proximate or adjacent to or butting against or fixed toor comprising the deformable member. The deformable member may beprovided between the fixing member and the seal. The method may compriseproviding a part of the seal between opposing legs of the deformablemember.

According to a fifth aspect of the present invention is a method forusing a seal system, such as the seal system according to the firstaspect. The method may comprise mounting the seal system to the pipe orother structure, such that at least a portion of the pipe or otherstructure is received within a passageway or annulus of the seal system.The method may comprise providing fluid to the seal so as to swell theseal. The seal may be swollen to seal against a bore wall or casing orconduit in which the seal system is located.

The method may comprise deforming the deformable member by swelling orexpanding the seal such that the swelling or expanding of the seal actsto deform the deformable member. The method may comprise deforming thedeformable member so as to increase the outer diameter or extent of thedeformable member. The method may comprise swelling or expanding aportion of the seal that is provided between legs of the deformablemember. The seal may be swollen or expanded so as to exert a force on atleast one leg and preferably both legs.

It will be appreciated that features analogous to those described abovein relation to any of the above aspects may be individually andseparably or in combination applicable to any of the other aspects.

Apparatus features analogous to those described above in relation to amethod and method features analogous to the use and construction ofthose described above in relation to an apparatus are also intended tofall within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are now described, by way of non-limiting example, and areillustrated in the following figures, in which:

FIG. 1 shows a longitudinal cross sectional view of a seal systemmounted in situ to a pipe;

FIG. 2 shows a longitudinal cross sectional view of an alternative sealsystem mounted in situ on a pipe;

FIG. 3 shows a longitudinal cross sectional view through a deformablemember for a seal system;

FIG. 4 shows a detail view of the cross section of the deformable membershown in FIG. 3;

FIG. 5 shows a perspective view of the deformable member shown in FIG.3;

FIG. 6 shows a longitudinal cross section through a fixing member for aseal system;

FIG. 7 shows a detail view of the cross section through the fixingmember shown in FIG. 5;

FIG. 8 shows a transverse cross section through the fixing member shownin FIG. 6;

FIG. 9 shows a perspective view of the fixing member shown in FIG. 6;

FIG. 10 shows a detail view of part of a seal system in an initial orunswollen state; and

FIG. 11 shows a detail view of part of a seal system in an operationalor swollen state.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a seal system 5 according to an embodiment of the presentinvention mounted on a pipe 10. The seal system 5 comprises a swellableseal 15 provided between a pair of end members 20 a, 20 b. In thisparticular embodiment, the seal 15 is bonded to the pipe 10 and both endmembers 20 a, 20 b. The seal system 5 is configured such that oppositeends 25 a, 25 b of the swellable seal 15 are bonded to correspondingfaces 30 a, 30 b of the end members 20 a, 20 b. The end members 20 a, 20b are also fixed to the pipe 10, for example, by bonding, grub screwsand/or the like.

The swellable seal 15 is in the form of a cylindrical sheath comprisinginner and outer surfaces 35 a, 35 b, wherein the ends 25 a, 25 b of theseal extend between the inner and outer surfaces 35 a, 35 b. The innersurface 35 a defines a longitudinal through passage that is open ateither end of the seal 15. The swellable seal 15 comprises a suitablematerial that is selectively or preferentially swellable by specificfluids, which optionally comprise fluids found downhole, such as oiland/or water or wet gas. The swellable seal 15 comprises, for example, asuitably swellable rubber or the like.

The end members 20 a, 20 b comprise cylindrical members having inner andouter surfaces 40 a, 40 b, the inner surface 40 a defining a throughpassage that is open at either end of the end member 20 a, 20 b. Thethrough passages of the end members 20 a, 20 b and the swellable seal 15align to form a longitudinal passage 45 through the seal system 5 thatis adapted to receive or accommodate the pipe 10, such that the sealsystem 5 forms a sheath that can be mounted on the pipe 10.

FIG. 2 shows an alternative embodiment of a seal system 5′ in situ,mounted on a pipe 10. The seal system 5′ of FIG. 2 is similar to that ofFIG. 1 and like components are indicated with corresponding referencenumerals. However, whereas the swellable seal 15 of the embodiment ofFIG. 1 is bonded to both the pipe 10 and the end members 20 a, 20 b, theswellable seal 15 of the seal system 5′ of FIG. 2 is only bonded to thepipe 10 and is free to move in relation to the end members 20 a, 20 b.Particularly, opposite ends 25 a, 25 b of the seal 15 are simplyprovided against, adjacent or proximate the corresponding faces 30 a, 30b of the end members 20 a, 20 b rather than being bonded to them.

In each of the above embodiments, the end members 20 a, 20 b eachcomprise a rigid fixing member, for example in the form of an annularend ring 50, and a deformable member 55, for example in the form of anannular elastomeric or non-elastomeric ring. The end members 20 a, 20 bare configured such that the deformable member 55 is provided betweenthe end ring 50 and the swellable seal 15 such that the deformablemember 55 forms at least part of the side face 30 a, 30 b of the endmember 20 a, 20 b that faces the swellable seal 15.

The deformable member 55 is shown in more detail in FIGS. 3, 4 and 5. Inparticular, the deformable member 55 comprises inner and outer surfaces65 a, 65 b and first and second sides 70 a, 70 b extending between theinner and outer surfaces 65 a, 65 b. The first side 70 a of thedeformable member 55 faces the seal 15 whilst the second side 70 b ofthe deformable member 55 faces the end ring 50. The inner surface 65 aof the deformable member 55 defines a through passage that forms part ofthe longitudinal passage 45 through the seal system 5, 5′ that receivesthe pipe 10.

The first side 70 a of the deformable member 55 comprises a sealreceiving groove in the form of an annular groove 75 that extends aroundthe first side 70 a of the deformable member 55. The groove 75 isdefined by first and second opposed legs 80 a, 80 b, the first leg 80 abeing provided radially outwardly of the second leg 80 b (i.e. furtherfrom the passage 45).

The groove 75 has an asymmetric cross sectional profile, with the first(i.e. the outer ward) leg 80 a being longer and extending further fromthe body of the deformable member 55 than the second leg 80 b. Inaddition, the first leg 80 a is provided at a shallower angle to thehorizontal 85 relative to the second leg 80 b.

In various embodiments, the first leg 80 a may extend at an angle to thehorizontal that is between 20% and 100% greater than the angle to thehorizontal at which the second leg 80 b extends. In a more specificexample, the first leg 80 a may extend at between 10° and 30° abovehorizontal, whilst the second leg 80 b may extend between 20° and 40°below horizontal. In the specific non-limiting example shown in FIG. 4,the first leg 80 a is angled at 20° above the horizontal, whilst thesecond leg 80 b is angled at 30° below the horizontal. In variousembodiments, the first leg 80 a can extend between 2 mm and 30 mm beyondthe second leg 80 b (in an undistorted state), and preferably between 3mm and 9 mm beyond. In the specific embodiment shown in FIG. 4, thefirst leg 80 a extends 5.8 mm (0.23 inches) beyond the second leg 80 b.The apex of the V-shaped groove 75 is radiused.

The second side 70 b of the deformable member comprises a protrudingportion 90 that is configured to fit into a receiving recess 95 in theend ring 50. The protruding portion 90 comprises a v-shaped protrusion.In certain embodiments, the surfaces 100 a, 100 b of the deformablemember 55 that form the v-shaped protrusion 90 are subtended by an angleof between 50° and 100° and preferably between 65° and 85°.

In the specific embodiment shown in FIG. 4, the surfaces 100 a, 100 b ofthe deformable member 55 that form the v-shaped protrusion 90 aresubtended by an angle of 76°.

Although various dimensions and angles of the deformable member 55 inthe undeformed state are described above, it will be appreciated that atleast some of the dimensions and angles of the deformable member 55 willbe varied depending on the application, e.g. depending on the diameterof pipe 10 upon which the seal system 5, 5′ is to be mounted, thediameter of the bore or conduit into which it is to be placed, thethickness of the seal 15, the seal quality required, and the like. Assuch, the above dimensions and angles are merely preferable and are notintended to be exhaustive.

The inner and outer surfaces 65 a, 65 b of the deformable member 55 areangled divergently from the second side 70 b to the first side 70 a. Inparticular, the deformable member 55 comprises a generally chevron ordistorted chevron shaped cross section.

The end ring 50 is shown in more detail in FIGS. 6 to 9. FIG. 6 shows across section through the end ring 50, whilst FIG. 7 shows more detailof the recess 95. FIG. 8 shows the end ring 50 in a transverse crosssection and FIG. 9 shows a perspective view of the end ring 50. The endring 50 comprises an annular member having outer and inner surfaces 105a, 105 b and first and second sides 110 a, 110 b disposed between theinner and outer surfaces 105 a, 105 b. The first side 110 a of the endring faces toward the deformable member 55 and the second side 110 b ofthe end ring 50 forms an outer end of the seal system 5, 5′. The innersurface 105 a of the end ring 50 defines a through passage thatpartially forms the passage 45 through the seal system 5, 5′ in whichthe pipe 10 is received in order to mount the seal system 5, 5′ in use.

The end ring 50 is provided with fixing means 115 for fixing the endring 50 on the pipe 10. In various embodiments, the fixing means 115 cancomprise the provision of suitable bonding between the end ring 50 andthe pipeline 10 and/or a plurality of threaded apertures for receivingset or grub screws that can be tightened so as to bear against the pipe10 to thereby fix the seal system 5, 5′ in place.

The first side 110 a of the end ring 50 (i.e. the side that faces thedeformable member 55) comprises the receiving recess 95 for receivingthe protruding portion 90 of the deformable member 15. The recess 95 isin the form of an annular groove that runs around the first side 110 aof the end ring 50. The recess 95 has a generally v-shaped crosssection, as shown in FIGS. 6 and 7. The apex of the recess 95 isradiused. The recess 95 is configured to open with an angle greater thanthe corresponding angle of the protrusion 90 of the deformable member55. In this example, the recess 95 is subtended by a 90° angle. In otherembodiments, the recess 95 may be subtended by an angle between 60° and120°.

As can be seen from FIG. 10, in an initial, unswollen state, the ends 25a of the swellable seal 15 is beveled or comprises a protruding portionsuch that at least a portion of the side 25 a of the seal 15 can bereceived within the groove 75 of the deformable member 55 between theopposing legs 80 a, 80 b. The other end 25 b of the swellable seal (notshown) may also be beveled.

In the unswollen state, the seal member 15 is sized such that a gap 120is left between the seal member 15 and the walls 125 of the bore, casingor conduit in which the seal system 5, 5′ and pipe is inserted in orderto permit easy insertion of the seal system 5, 5′. Once the seal system5, 5′ is located in the desired location, a suitable fluid that resultsin swelling of the swellable seal 15 is provided to the swellable seal15 through the bore, casing or conduit.

The resulting swelling of the swellable seal 15 closes the gap 120between the swellable seal 15 and the wall 125 of the bore, conduit orcasing. In addition, the swelling of the seal 15 applies pressure on theopposing legs 80 a, 80 b of the groove 75 of the deformable member 55.This has the effect of deforming the deformable member 55 by forcing thelegs 80 a, 80 b apart. As a result, the outer diameter of the deformablemember 55 expands. Specifically, the first leg 80 a is pushed outwardlytowards and into contact with the wall 125 of the bore, casing orconduit, as can be seen in FIG. 11. As a result, the gap 120 between theend members 20 a, 20 b and the wall 125 of the bore, casing or conduitis substantially eliminated or at least greatly reduced. In this way,the deformable member acts as a back-up or additional seal.

Furthermore, extrusion of the swellable seal 15 past the end members 20a, 20 b due to pressure differentials or flow found downhole issubstantially reduced or eliminated. In this way, the deformable member55 acts as an anti-extrusion ring. Furthermore, since the deformablemember 55 is formed from a non-metallic material, it has enough give tominimise the risk of the deformable member 55 causing the seal system 5,5′ to stick in the hole but has enough strength to provide additionalsupport to the swellable seal 15, biasing the seal 15 into an optimalposition and providing additional or back-up sealing between the pipe 10and the walls of the borehole, conduit or casing. In this way, improvedseal quality can be obtained, which may permit the use of the sealsystem 5, 5′ with higher pressure differentials or alternatively, maypermit the use of a shorter seal system at a similar pressure range. Theshape of the deformable member 55 is such that the longer first leg 80 aallows the gap 120 to the wall 125 of the conduit, bore or casing to bemore reliably bridged.

Furthermore, the shape of the deformable member 55 is such that thehigher the pressure that is applied to the legs 80 a, 80 b, the moreforcefully the second leg 80 b is forced against the pipe 10 and thefirst leg 80 a is forced against the wall 125 of the bore, conduit orcasing. As such, the higher the pressure that is applied, the tighterthe seal that is formed by the deformable member 55, thereby permittinguse at a higher operating pressure differentials. By providing therecess 95 in the end ring 50, the deformable member 55 can be moresecurely located and additional support is provided to the deformablemember 55 whilst allowing the deformable member 55 to suitably flex anddeform.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the invention. Indeed the novel methods and systems describedherein may be embodied in a variety of other forms. Furthermore, variousomissions, substitutions and changes in the form of the methods andsystems described herein may be made without departing from the spiritof the invention. The accompanying claims and their equivalents areintended to cover such forms and modifications as would fall within thescope of the invention.

For example, whilst certain preferential dimensions and angles aredescribed herein, it will be appreciated that the size and angles of thecomponents of the seal system 5, 5′ will vary depending on theapplication, e.g. with the size of the pipe, the size of the bore orconduit and the like.

In addition, embodiments have been described herein wherein the sealreceiving recess is advantageously in the form of a groove definedbetween first and second legs of the deformable member. This arrangementhas advantages such as improved sealing since pressure applied to thefirst and second legs by the swellable member acts to force one leg intocontact with the pipe and the other leg into contact with the wall orcasing of the bore, conduit or hole. However, it will be appreciatedthat other configurations may be used. For example, the swellable membermay be adhered, bonded or otherwise fixed to the pipe and the swellablemember may only be provided with one leg (e.g. the upper or outer leg),such that the recess is defined by the leg of the deformable member andthe surface of the pipe. In this way, the swelling of the seal acts topush the single leg radially outwardly in order to close the gap betweenthe deformable member and the wall of casing of the bore, conduit orhole.

Furthermore, whilst various components of the seal system 5, 5′ aredescribed as being constructed of certain materials, it will beappreciated that the components may be fabricated from other suitablematerials.

In addition, whilst the seal system 5, 5′ is described as beingmountable on a pipe 10, it will be appreciated that the seal system isalso mountable to other structures such as mandrels, cables, struts, andthe like.

Whilst the above examples have been described in relation to the sealsystem 5, 5′ being used in a bore, it will be appreciated that the sealsystem may also be used in other locations, such as in casings,conduits, holes, channels and the like. In addition, whilst the sealreceiving recess 75 in specific embodiments is advantageously a groove,it will be appreciated that other shapes or forms of recess could alsobe used.

Furthermore, whilst the seal 15 is described as being advantageouslyswellable, it will be appreciated that other seals, such as expandableseals, that are expandable or movable in order to deform the deformablemember could be used. Examples of such alternative seals may includeinflatable or pressurizable seals, seals that comprise a compressedresilient material that are expandable when released and the like.

The invention claimed is:
 1. A downhole seal system comprising: adeformable member including a body and first and second legs extendingaxially from the body, the first leg provided radially outwardly of thesecond leg to define an annular seal receiving groove radially betweenthe first and second legs; an expandable seal including an end portionreceived within the annular seal receiving groove, the expandable sealbeing expandable so as to deform the deformable member and increase aradial separation of at least portions of the first and second legs; anda fixing member configured to be fixed relative to the deformable memberso as to securely locate the deformable member in the seal system, thefixing member comprising a recess for at least partially receiving thedeformable member.
 2. The seal system according to claim 1, wherein theexpandable seal is a swellable seal.
 3. The seal system according toclaim 1, wherein the seal system comprises first and second fixingmembers, the deformable member being within the first fixing member anda further deformable member being within the second fixing member, atleast part of the expandable seal being provided axially between thefixing members.
 4. The seal system according to claim 1, wherein theexpandable seal is adapted for sealing against walls or casing of ahole, conduit or borehole in which the seal system is located when theseal is swollen.
 5. The seal system according to claim 1, wherein thedeformable member comprises a non-metallic material.
 6. The seal systemaccording to claim 1, wherein the annular seal receiving groove isasymmetric in cross section.
 7. The seal system according to claim 1,wherein one of the first and second legs extends axially further fromthe body of the deformable member than the other of the first and secondlegs.
 8. The seal system according to claim 1, wherein the deformablemember is provided between the fixing member and the expandable seal. 9.The seal system according to claim 1, wherein the fixing member isconfigured to be fixed to a pipe or other structure upon which the sealsystem is mounted.
 10. The seal system according to claim 1, wherein asurface of the deformable member that faces the fixing member comprisesa protruding profile shaped to fit into the recess of the fixing member.11. The seal system according to claim 1, wherein the deformable memberhas a cross section in the form of a chevron or a distorted orasymmetric chevron.
 12. The seal system according to claim 1, whereinthe end portion of the expandable seal has a profile which correspondsto the profile of the annular seal receiving groove of the deformablemember.
 13. The seal system according to claim 1, wherein the sealsystem is configured such that as the expandable seal expands, theexpandable seal applies a radially outward force to the first leg of thedeformable member and a radially inwardly force to the second leg of thedeformable member.
 14. The seal system according to claim 1, wherein thedeformable member comprises a non-metallic ring.
 15. The seal systemaccording to claim 1, wherein the annular seal receiving groove is atleast partially defined between the first and second legs and one of thefirst and second legs extends further from the body of the deformablemember than the other of the first and second legs.
 16. The seal systemaccording to claim 1, wherein a surface of the deformable memberopposite a surface on which the seal receiving groove is providedcomprises a protruding profile.
 17. The seal system according to claim1, wherein the fixing member is rigid and configured to be fixed to apipe or other structure upon which the seal system is mounted.
 18. Theseal system according to claim 1, wherein one of the first and secondlegs extends from the body of the deformable member at a different angleto the other of the first and second legs.
 19. A method for producingthe seal system according to claim 1, the method comprising providingthe deformable member having the annular seal receiving groove betweenthe fixing member and the expandable seal, wherein the fixing member isrigid and configured to be fixed to a pipe or other structure upon whichthe seal system is mounted.
 20. The method according to claim 19,comprising providing a part of the expandable seal within the annularseal receiving groove in the deformable member.
 21. A method for usingthe seal system according to claim 1, the method comprising: mountingthe seal system to a pipe or other structure, such that at least aportion of the pipe or other structure is received within a passagewayof the seal system; and expanding the expandable seal of the seal systemto deform the deformable member so as to increase at least one of anouter diameter or an extent of the deformable member.